Arrangements in polyphase modular vacuum switches having common operating means



Feb. 22, 1966 G MESTER 3236,918

i n ARRANGEMENTS IN POLYPHASE MODULAR VACUUM SWITCHES HAVING COMMONOPERATING MEANS Filed April 2, 1962 3 Sheets-Sheet 2 Feb. 22, 1966 G. N.LESTER 3 236,978

9 ARRANGEMENTS IN POLYEHASE MODULAR VACUUM SWITCHES HAVING COMMONOPERATING MEANS Filed April 2, 1962 3 Sheets-Sheet 3 United StatesPatent O ARRANGEMENTS IN POLYPHASE MODULAR VACUUM SWITCHES HAVING COMMONOP- ERATING MEANS George N. Lester, Westwood, Mass., assignor to Allis-Chalmers Manufacturing Company, Milwaukee, Wis.

Filed Apr. 2, 1962, Ser. No. 184,220 4 Claims. (Cl. 200-144) Thisinvention pertains to electric circuit breakers and more particularly topolyphase circuit breakers utilizing a plurality of vacuum switchmodules arranged for actuation by a common operating means.

In accordance with the invention claimed, a new and improved polyphasecircuit breaker structure is provided comprising a plurality of circuitinterrupting devices wherein at least one of the devices is employed ineach phase of the circuit. Each of the devices is mounted within avacuumized envelope and comprises a pair of cooperating separablecontacts. One of the contacts of each of the pairs of contacts issupported for movement in directions inwardly and outwardly of theenvelope. Means common to all of the phases of the polyphase circuitbreaker structure is provided for operating the movable contacts.

The principal object of this invention is the provision of an improvedmultiphase circuit breaker structure for effecting synchronous operationof all of the contacts of all of the interrupting devices in all of thephases of the electric circuit.

Another object of this invention is to provide a new and improved vacuumtype circuit breaker structure comprising a plurality of pairs ofcooperating arcing contacts arranged in electrical and spatialarrangement on a common insulating column.

A further object of this invention is to provide a new and improvedvacuum type circuit breaker structure comprising a plurality of pairs otcooperating contacts wherein the modules of each phase of the polyphasecircuit are separately but simultaneously interrupted by a commonactuating means.

A still further object of this invention is to provide a new andimproved circuit interrupting structure including in electrical andspatial relation one or more movable contacts in one or more vacuumizedenvelopes wherein the movable contacts of each phase of a polyphasecircuit are adapted to be operated through the intermediary of a commonrotating insulating structure.

A still further object of this invention is to provide a new andimproved vacuum type circuit interrupting device employing a pluralityof modules in spatial series relationship for each phase of a polyphasecircuit breaker structure wherein the contacts of the devices of eachphase are supported for movement in opposed directions.

A still further object of this invention is to provide a new andimproved polyphase circuit breaker structure wherein a plurality ofcircuit interrupting devices each operable within a vacuum are mountedon a common insulating column and each of the devices in each phase aremounted at the same distance from the base ofthe column.

A still further object of this invention is to provide a new andimproved polyphase circuit breaker structure employing a plurality ofvacuum switch interrupting devices arranged on a single column whereinthe devices are arranged to extend transversely from the insulatingcolumn.

A still further object of this invention is to provide a polyp-hasecircuit breaker structure employing a plurality of vacuum type circuitinterrupting devices wherein the devices of each phase have theirlongitudinal axes arranged transversely to each other.

A still further object of this invention is to provide a new andimproved polyphase circuit breaker structure employing a plurality ofvacuum type circuit interrupting devices mounted on a single insulatingcolumn wherein the devices of each phase are arranged with theirlongitudinal axes in parallel planes.

A still further object of this invention is to provide an improvedvacuum type circuit breaker structure for interrupting circuits having avery high operating voltage which is simple, reliable in operation andrelatively inexpensive to manufacture Objects and advantages other thanthose described above will be apparent from the following descriptionwhen read in connection with the accompanying drawings in which:

FIG. 1 is an isometric view of a vacuumized polyphase circuit breakerstructure mounted on a common insulating column and operated by a rotaryactuating mechanism and embodying the invention;

FIG. 2 is a partial cross sectional view of one phase of the polyphasecircuit breaker structure shown in FIG. l taken along the line II-II;

FIG. 3 is a side view of the rotary actuating mechanism shown in thebase of the column ofthe structure illustrated in FIG. l;

FIG. 4 is a bottom view of FIG. 3 taken along the line IV-IV;

FIG. 5 is a modification of the structure shown in FIGS. l through 4wherein the longitudinal axes of the vacuumized circuit interruptingdevices of each phase are arranged parallel to each other and at acommon distance from the base of the structure; and

FIG. 6 is a cross sectional view of FIG. 5 taken along the line VI-VI.

FIG. l illustrates an isometric View of a polyphase circuit breakerstructure 1t). Structure 10 comprises a plurality of identicalvacuumized circuit interrupting devices 11a, 11b, 11e, 11d, 11e and117i, wherein like parts are provided with similar reference charactersand wherein the vacuum switches or interrupters are mounted on astructural column 12. Each of the vacuum interrupters of each phase arearranged in series spatial arrangement with their longitudinal axesarranged transversely to each other and to column 12. The circuitbreakers in each of phase A, B and C, as shown in FIG. l are arranged incommon horizontal planes but different vertical planes. Column 12 ismounted on a base 13 which supports or houses a motor 14 and crankarrangement 15 for actuating an insulating shaft 16 which is mounted forrotation in column 12 as shown in FIGS. 2, 3 and 4. Column 12 comprisesa plurality of hollow insulators 17 which are separated from each otherby hollow spacers forming metallic casing 18. The insulators 17 andcasings 18 are all mounted in axial alignment for receiving andsupporting shaft 16.

Casing 18 is arranged to have bolted thereto a plurality of interruptingstructures in module form. One of the interrupters i-s shown in FIG. 2in cross section. Each interrupter may comprise a cylindrical casing 2t)closed at one end by a cover 21 bolted by suitable means such as bolts24 to a tlange 22 surrounding cylinder 20 and secured to casing 18 bysuitable means such as bolts 24 attaching flange 25 surrounding theother end of cylinder 20 to casing 18. Cover 21 serves as a means forreceiving and positioning one end of a vacuum interrupter structure 26in cylinder 20 as well as an electrical contact `for interconnecting thevacuum interrupters of a given pole structure.

As shown in FIG. 2 the vacuum interrupter struc- `ture 26 comprises acylindrical envelope 27 which may be formed, for example, of a suitablevitreous material. One end of envelope 27 is provided with an annularrim 28 to which is xedly secured in vacuum tight connection thereto oneend of a ring or flange 29. A metallic cap 3) is sealed throughout itsedge to the other` end of flange 29 in the manner shown in FIG, 2. Cap30 supports a relatively fixed contact 31 which is arranged to extendalong the longitudinal axis of envelope 27 and is substantially rigidlysupported so as to restrict longitudinal or lateral movement thereof.Cap 30 may support a tubular venting passage (not shown) through whichenvelope 27 is evacuated and sealed yoff in the usual way. The oppositeend of envelope 27 is provided with an annular rim 33 to which islixedly secured in a vacuum tight connection one end of a ring or ange34. A tube or retainer 35 is sealed throughout its rim in a vacuum tightconnection to flange 34 in the manner shown. A metallic cylindricallyshaped bellows 36 is fixedly secured in a Vacuum tight connection at oneend thereof to retainer 35. The other end of bellows 36 surrounds and islixedly attached in a vacuum tight connection to a movable contact 37which is arranged to extend through retainer 35 into envelope 27 and incooperating relationship with contact 31.

The relatively movable cooperating contacts 31 and 37 may be made of anysuitable material which, for example, may be but is not limited totungsten or tungsten alloys. As shown in FIG. 2 contact 37 is arrangedfor longitudinal movement a limited predetermined distance by thecontact actuating mechanism comprising motor 14 and the crankarrangement 15 shown in FIG. 3 while being restrained from lateraldisplacement.

In order to control the arcing products emitted upon separation of theengaging surfaces of contacts 31 and 37 shown in FIG. 2 a cylindricalcup shaped tube or shield 39 is provided around and spaced from contact37. Shield 39 is arranged to extend beyond the adjacent ends of thecontacts so as to surround at least a part of contact 31 when in contactengaging position. Shield 39 may be formed of glass or any :suitablemetallic or nonmetallic material.

Upon actuation of movable contact 37 in axial contact engaging orcontact disengaging direction, bellows 36 deflects, allowing restrictedlongitudinal movement of contact 37. The required range of movement ofcontact 37 is very small. With onliI 3/16 of an inch separation betweenengaging surfaces of contacts 31 and 37 a current of several thousandamperes at an A,C. voltage of 18,000 can be safely interrupted by eachvacuum interrupter element of a pole structure. The interrupter cancontinuously conduct current of several hundred amperes. Since normalatmospheric pressure tends to expand the bellows into envelope 27, theatmospheric `pressure may be utilized to help hold or assist in holdingthe contacts together in normally closed position or to speedily closethe gap between them upon release of an externally applied contactseparating force.

Movable contacts 37 of the module comprising Vacuum interrupters 11)cand 11e as shown in FIG. 2, extend into casing 18 and are attached toshaft 16. If the module is arranged in a common plane a clamping means40 having a pair of laterally extending arms 41 and 42 is provided forattaching the movable contacts 37 to shaft 16. Each of the arms 41 and42 is loosely mountted on contacts 37 and is biased away from the arcingtip end thereof against nuts 44, 44', threadedly mounted on shafts 37,by springs 45, 45. Springs 45, 45 are axially mounted on shafts 37 andextend between co1- lars 46, 46 on shafts 37 and the arms of clamp 40.Spring type conductor members 47, 47 are attached at one end to shafts37 between nuts 44 and 48 and between nuts 44 and 48', respectively, andat the other end to casing 18. Members 47, 47 form a dual function of anelectrical contact and a spring biasing means acting to aid theatmospheric pressure in normally holding contacts 31 and 37 of thevacuum interrupters in engagement.

Clamp 40 which is fxedly attached to shaft 16 is rotated clockwise asshown in FIG. 2 upon rotation of shaft 16. Rotation of clamp 46 causesarms 41, 42

thereof to press against nuts 44, 44 on the ends of contacts 37 therebyactuating them longitudinally of envelopes 27 to separate the contacts31 and 37. With the structure shown in FIGS. l and 2 the movablecontacts of all of the modules comprising vacuum interrupters 11athrough 11]t are actuated substantially simultaneously in opposeddirections inwardly and outwardly of envelopes 27. The inward andoutward movements of the movable contacts of the modules are provided byro* tation of shaft 16 by the crank arrangement 15 as shown in FIG. 3.

Shaft 16 is rotated through a sector of a circle. This motion isclockwise with reference to FIG. 4 in order to close the arcing contactsof the modules comprising interrupters 11a through 11jc andcounterclockwise in order to open these arcing contacts. The rotation ofshaft 16 is accomplished by motor 14 through the crank arrangement 15shown in FIGS. 3 and 4. Shaft 50 of motor 14 is provided with a gear 51which is in meshing engagement with a gear 52 mounted on shaft 53. Shaft53 is parallelly arranged with shaft and is rotatably mounted in fixedbearing surfaces 54 and 55. A gear 56 ixedly mounted on shaft 53 is inmeshing engagement with a gear 57 which is keyed to a sleeve 58 which isrotatably mounted on shaft 50. Sleeve 58 has attached thereto a crankarm 59. Crank arm 59 has mounted thereon a pin 60 which engages a slot61 forming a lost motion connection in a link 62. Link 62 is pivotallyattached to a crank arm 63 of crank 64 which is rotatably mounted onshaft 16, as shown. Crank arm 65 forming a part of crank 64 is pivotallyattached to a rotatably mounted spring biasing means 66. Spring biasingmeans 66 comprises a shaft 67 pivotally attached at one end to crank arm65 and reciprocally mounted at the other end in an aperture 79 in ashaft structure 68.

As shown in FIG. 3 shaft structure 68 comprises shaft portions 69 and 70which are relatively movable one to the other. The shaft structure 68 isrotatably mounted at its ends on base 13 of the circuit breakerstructure 10. A spring 71 is mounted around shaft 67 and bears against acollar 72 at one end of shaft 67 and a collar 73 slidably mounted onshaft 67 at the other end thereof.

Shaft 16 has ixedly mounted thereon adjacent to crank arm 65 a plate 74for rotation therewith. Plate 74 is provided with pins 75 and 76extending transversely therefrom which form limit stops for crank arm65. A spring biasing means 77 similar to the spring biasing means 66 isattached to plate 74 and shaft structure 68. The spring biasing means 77comprises a shaft 78 pivotally attached at one end to plate 74 andreciprocally mounted at the other end in an aperture 79 in shaft portion70 of shaft structure 68. A spring 80 is mounted around shaft 78 andbears against a collar 81 at one end of shaft 78 and a collar 82slidably mounted on shaft 78 at the other end thereof.

FIG. 4 shows the crank arrangement 15 in the contact open position.Plate 74 is biased by crank arm 65 acting against pin 75 against a stop83 on the circuit breaker frame structure. As pin 60 is rotatedclockwise about its center of rotation by motor 14 link 62 travels tothe left and crank 64 rotates clockwise until it engages pin 76. At thispoint spring 71 is slightly over center with respect to a line betweenits support at shaft structure 68 and the axis of shaft 16.

The crank arrangement 15 is now ready to snap contacts 31 and 37 closedthrough actuation of shaft 16, clamp 40 and arms 41 and 42. In the readyto close position spring 71 is fully charged. Since link 62 is providedwith a lost motion slot 61, crank 64 is not retarded by pin 60 in itssudden motion to the left. This motion is caused by crank 64 which isdriven by spring 71 in the clockwise direction. As crank 64 snaps towardthe closed Contact position, it is forced against pin 76. Plate 74 inturn is then forced against stop 84 on the circuit breaker structure.Shaft 16, which is fastened to plate 74, on being rotated clockwisetransmits the closing stroke to the movable circuit breaker contact 37.By suitable control switches the control circuit for motor 14 is cut olfat or near the end of the crank arrangements stroke.

As pin 60 is rotated by motor 14 further in the clockwise directioncrank 64 rotates counterclockwise. Since the crank arrangement issymmetrical about a line through the support of spring 71 and the axisof shaft 16, the opening operation is the image of the closing carriedout in the counterclockwise direction by crank 64, plate 74 and shaft16.

FIGS. 5 and 6 illustrate a modification of the structure shown in FIGS.1 through 4 wherein the vacuum interrupters 11a through 111 are mountedon a column 12 comprising hollow insulators 17' separated by casings 18.The longitudinal axes of the vacuumized interrupters of each of thephases A, B and C are arranged parallel to each other and at a commondistance from the base 13 of the structural column 12. The vacuuminterrupters 11a through 11f are identical to those shown and describedfor FIGS. 1 through 4 except that they are all arranged in parallelvertical planes. FIG. 6 illustrates a cross sectional view of thestructure shown in FIG. 5 wherein the arms 41 and 42 are bent from theform shown in FIG. 2 to actuate contacts 37 of the module comprisingvacuum interrupters 11e and 11f in parallel spaced directionslongitudinally of vacuum interrupters 11e and 11f.

Although but a few embodiments of the present invention have beenillustrated and described, it will be apparent to those skilled in theart that various changes and modifications may be made therein withoutdeparting from the spirit of the invention or from the scope of theappended claims.

Having now particularly described and ascertained the nature of my saidinvention and the manner in which it is to be performed, I declare thatwhat I claim is:

1. A polyphase circuit breaker comprising at least a pair ofinterconnected circuit interrupting devices for each phase, each of saiddevices being mounted within a vacuumized envelope and comprising a pairof cooperating separable contacts, one of said contacts of each of saidpairs of contacts being supported for movement in directions inwardlyand outwardly of said envelope, a single column insulating means forsupporting each of said devices of each of said phases, said devices ofeach of said phases having their longitudinal axes arranged transverse-Ily to each other, and means common to all of said devices Aforoperating said movable contacts.

2. A polyphase circuit breaker comprising at least a pair of.interonneted circuit interrupting devices for each phase, each of saiddevices being mounted within a vacuumized envelope and comprising a pairof cooperating separable contacts, one of said contacts of each of saidpairs of contacts being supported for movement in directions inwardlyand outwardly of said envelope, a single column insulating means forsupporting each of said devices, said devices of each phase having theirlongitudinal axes arranged in parallel planes, said planes beingtransverse to the axis of said column, and means common to all of saidphases for operating said movable contacts.

3. A polyphase circuit breaker comprising a plurality of interconnectedcircuit interrupting devices for each phase, each of said devices beingmounted within a vacuumized envelope and comprising a pair ofcooperating separable contacts, one of said contacts of each of saidpairs of contacts being supported for movement in directions inwardlyand outwardly of said envelope, a single insulating means for supportingsaid devices of each of said phases in a column, said devices of each ofsaid phases being mounted transversely to each other in a common plane,and means common to all of said devices arranged within said column foroperating said movable contacts.

4. A polyphase circuit breaker comprising a plurality of interconnectedcircuit interrupting devices for each phase, each of said devices beingmounted within a vacuumized envelope and comprising a pair ofcooperating separable contacts, one of said contacts of each of saidpairs of contacts being supported for movement in directions inwardlyand outwardly of said envelope, a single insulating means for supportingsaid devices of each of said phases in a column, said devices of each ofsaid phases being mounted in different vertical planes, and means commonto all of said devices arranged within said column for operating saidmovable contacts.

References Cited by the Examiner UNITED STATES PATENTS 1,801,736 4/1931Greenwood 200-144 2,906,841 9/ 1959 Jennings 200-144 2,917,596 12/1959Jennings et al. 200-144 3,159,731 12/1964 Luehring 200-144 FOREIGNPATENTS 356,221 9/ 1931 Great Britain. 599,970 3/ 1948 Great Britain.

KATHLEEN H. CLAFFY, Primary Examiner.

ROBERT K. SCHAEFER, ROBERT S. MACON,

Examiners.

1. A POLYPHASE CIRCUIT BREAKER COMPRISING AT LEAST A PAIR OFINTERCONNECTED CIRCUIT INTERRUPTING DEVICES FOR EACH PHASE, EACH OF SAIDDEVICES BEING MOUNTED WITHIN A VACUUMIZED ENVELOPE AND COMPRISING A PAIROF COOPERATING SEPARABLE CONTACTS, ONE OF SAID CONTACTS OF EACH OF SAIDPAIRS OF CONTACTS BEING SUPPORTED FOR MOVEMENT IN DIRECTIONS INWARDLYAND OUTWARDLY OF SAID ENVELOPE, A SINGLE COLUMN INSULATING MEANS FORSUPPORTING EACH OF SAID DEVICES OF EACH OF SAID PHASES, SAID DEVICES OFEACH OF SAID PHASES HAVING THEIR LONGITUDINAL AXES ARRANGED TRANSVERSELYTO EACH OTHER, AND MEANS COMMON TO ALL OF SAID DEVICES FOR OPERATINGSAID MOVABLE CONTACTS.